Saturn - A gas giant known for its clearly visible surrounding rings, unlike the other gas giants whose rings are rather dim. Saturn is the second largest planet in the Sol System. Its practical uses to the UNSC are limited, and therefore it is mostly just a tourist destination.[2]

Uranus - An icy gas giant about twice as far away as Saturn from Sol. Its distance from Sol makes it of little use to the UNSC.

Neptune - Furthest away from Sol, it is another icy gas giant similar to Uranus.

Ceres - The largest asteroid to have ever been discovered by Humanity.

Eris - Currently the largest Dwarf Planet known. It is almost 10% larger than Pluto in diameter.

Pluto - In the 1930s, Pluto was discovered and named a planet. Many years later in 2006, scientists debated over if it was really big enough to actually be considered a planet, and gained some ground in the fact that it had a moon, Charon, but after much talk, it was declassified. The Pluto Slipstream Monitoring Station Democritus is stationed in orbit around it. On November 3, 2552, the Monitoring Station detected Cortana's signal in Slipspace with Dr. Halsey's message to Lord Hood. Pluto has five moons: Nix, Hydra, Kerberos, Styx and the largest of its satellites Charon.

Haumea - The most notable feature is its highly elliptical shape.

Makemake - The second most distant dwarf planet, its lack of moons mean it and Ceres are the only two known dwarf planets orbiting Sol without moons.